Known as a conventional laboratory dish (Schale) is a partitioned laboratory dish defined as an incubation container disclosed in Japanese Patent Application Laid-Open No. 8-52366. The partitioned laboratory dish includes incubation chambers formed by partitioning an interior of a container of the laboratory dish with a for-the-use-of-Schale partitioning member that eliminates a necessity of pouring culture mediums separately into the partitioned incubation chambers.
To be specific, the partitioning member of the partitioned laboratory dish has a configuration that a whole or part of a partition base thereof does not tightly fit to a bottom surface of the laboratory dish, with the result that a plurality of sections (incubation chambers) in the interior of the partitioned laboratory dish communicate with each other at the bottom portion, and the culture medium, when poured into one section, spreads into all other sections within the same laboratory dish.
The partitioned laboratory dish is filled with a liquid containing a nutrient called a culture medium, and the cells are incubated on the bottom surface etc of the laboratory dish. The use of an inverted microscope enables observation of the cells on the bottom surface of the laboratory dish. A phase difference observation method enables a difference in refractive index between the cells to be converted into a contrast, whereby transparent cultured cells can be observed as they remain living.
The conventional laboratory dish exhibits such a phenomenon that when filled with the liquid defined as the culture medium, the liquid surface is not flat, and a liquid level in the vicinity of a wall surface of the partitioning member rises. The liquid level has a curvature, and hence a lens effect (this is called meniscus effect) occurs. Consequently, a phase difference illumination system gets lost its function, and a sufficient contrast is not acquired. None of problems arise in an area where the liquid surface existing sufficiently away from the wall surface is flat, however, there is a hindrance to the observation of the cells close to the wall surface of the partitioning member. Especially at the central portion of the partitioned laboratory dish, the partitioning member has a cross-shaped intersection, which hinders the observation.
Another problem of the conventional partitioned laboratory dish is that the partitioning member thereof has a gap at the bottom portion of the laboratory dish, and it is therefore impossible to observe a difference in reaction to the culture mediums between the cells by inputting the culture mediums under different conditions in the respective sections.
It is an object of the present invention, which was devised under such circumstances, to provide a laboratory dish capable of restraining the meniscus effect caused by the partitioning member of the partitioned laboratory dish and easily pouring and exchanging the liquid to be poured into the laboratory dish.